package com.kgcx.opc.rabbit.json;

import com.alibaba.fastjson.JSON;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.amqp.support.converter.AbstractMessageConverter;
import org.springframework.amqp.support.converter.MessageConversionException;

import java.io.UnsupportedEncodingException;

/**
 * Created by luban
 * User: lic
 * Date: 2017/11/1
 * Time: 9:25
 * Desc 消息json转换
 * @author lic
 */
public class FastJsonMessageConverter extends AbstractMessageConverter{
    public static final String  DEFAULT_CHARSET = "UTF-8";
    private volatile String defaultCharset  = DEFAULT_CHARSET;
    public FastJsonMessageConverter() {
        super();
        //init();
    }
    public void setDefaultCharset(String defaultCharset) {
        this.defaultCharset = (defaultCharset != null) ? defaultCharset : DEFAULT_CHARSET;
    }

    @Override
    public Object fromMessage(Message message) throws MessageConversionException {
        return null;
    }

    public <T> T fromMessage(Message message,T t) {
        String json = "";
        try {
            json = new String(message.getBody(),defaultCharset);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return (T) JSON.parseObject(json, t.getClass());
    }

    @Override
    protected Message createMessage(Object objectToConvert, MessageProperties messageProperties) throws MessageConversionException {
        byte[] bytes = null;
        try {
            String jsonString = JSON.toJSONString(objectToConvert);
            bytes = jsonString.getBytes(this.defaultCharset);
        } catch (UnsupportedEncodingException e) {
            throw new MessageConversionException("Failed to convert Message content", e);
        }
        messageProperties.setContentType(MessageProperties.CONTENT_TYPE_JSON);
        messageProperties.setContentEncoding(this.defaultCharset);
        if (bytes != null) {
            messageProperties.setContentLength(bytes.length);
        }
        return new Message(bytes, messageProperties);
    }
}
